JP2554408B2 - Automatic cylindrical grinding method and device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention automatically performs cylindrical grinding of an ingot, orientation flat (abbreviated as orientation flat in this specification) grinding, and stepped grinding of an ingot tail portion for cutting a sample for lifetime measurement. The present invention relates to an automatic cylindrical grinding method and apparatus which can be performed.

[0002]

2. Description of the Related Art A semiconductor substrate used for manufacturing a semiconductor integrated circuit device is a round rod-shaped single crystal produced by a single crystal growth method, that is, a Czochralski method (CZ method) or a floating zone melting method (FZ method). After centering the ingot, the outer periphery is ground by a cylindrical grinder to a diameter of a predetermined size and an orientation flat is cut at a predetermined position to obtain a substantially cylindrical single crystal ingot, which is a substantially cylindrical single crystal ingot. Is cut at a substantially right angle to its major axis direction, that is, cut in accordance with a predetermined crystallographic direction, both sides of a substantially disk-shaped product obtained by cutting are lapped and etched, and finally one side thereof is polished. can get.

Conventionally, the cylindrical grinding and orientation flat grinding of the above-mentioned single crystal ingot have been carried out independently, and the cutting of the sample for measuring the lifetime has also been carried out as a separate process, which is troublesome. The processing efficiency was poor.

[0004]

SUMMARY OF THE INVENTION The present invention has been invented in view of the above-mentioned prior art, and has a tail step for cutting a sample for cylindrical grinding, orientation flat grinding and lifetime measurement of a single crystal ingot. An object of the present invention is to provide an automatic cylindrical grinding method and apparatus capable of continuously and automatically performing grinding.

[0005]

In order to solve the above problems, the automatic cylindrical grinding method of the present invention comprises (a) a step of setting an ingot at a predetermined position, and (b) a diameter of the set ingot. A step, (c) a step of determining whether or not orientation flat grinding is performed on this ingot, and (d)
A step of detecting and storing the crystal habit line position of this ingot,
(E) cylindrically grinding the ingot, (f) measuring the diameter of the ground ingot,
(G) determining whether or not to perform tail step grinding on this ingot, (h) measuring the shape of the tail of this ingot, and (i) performing tail step grinding on this ingot. , (J) determining again whether or not to perform orientation flat grinding on this ingot, (k) aligning this ingot with a crystal habit line storage position, and (l) determining the orientation of the cylindrically ground ingot. X-ray diffraction peak confirming step, (m) adjusting the angle of this ingot to match the orientation flat grinding surface with the orientation flat grinding means , and (n) grinding this ingot to form the orientation flat surface. And (o) a step of measuring the formed orientation flat cutting margin, and (p) a step of taking out an ingot that has been subjected to cylindrical grinding and has formed an orientation flat surface, based on the input grinding information, When the cylindrical grinding, the orientation flat grinding, and the tail stepped grinding are performed on the ingot, the steps (a) to (p) are performed, and when the orientation flat grinding is not performed, the above (d) and (k) to (o) are performed. The step (3) is omitted, and the steps (h) and (i) are omitted when the stepped tail grinding is not performed.

The automatic cylindrical grinding apparatus of the present invention has means for inputting grinding information, means for setting and removing an ingot, means for stopping rotation of the ingot according to the input grinding information, and diameter of the ingot. Means for measuring, means for judging the input grinding information, means for detecting the crystal habit line position of the ingot, means for storing the detected crystal habit line position of the ingot, cylindrical grinding of the ingot and tail step A grinding means for performing adhering grinding, a means for measuring the ingot tail shape, a means for confirming the orientation of the ground ingot by an X-ray diffraction peak, an orientation flat grinding means for grinding the ingot to form an orientation flat surface, A command unit for sequentially operating each means based on the input grinding information is provided so that the above-described automatic cylindrical grinding method can be executed. It is.

[0007]

In the present invention, it is necessary to detect the crystal habit line of the ingot and identify the predetermined orientation flat orientation surface, that is, the orientation flat grinding surface by the X-ray diffraction peak (X-ray measurement) with the position as the reference plane. Based on this recognition, it became possible to automatically perform orientation flat grinding of each ingot.

Also, in identifying the orientation flat grinding surface, X
If the X-ray diffraction peak position matches the orientation flat orientation as it is, the orientation flat grinding may be performed as it is, but if the X-ray diffraction peak position does not match the orientation flat orientation, X
The orientation flat grinding is performed after the orientation detected by the line measurement is aligned with the orientation flat orientation to be obtained by rotationally positioning the designated angle.

In the case of the above method of detecting the X-ray diffraction peak position as it is as the orientation flat orientation, it was necessary to adjust the incident angle θ of the X-ray according to the orientation flat orientation to be detected. When the angle is adjusted after using as a reference surface, there is an advantage that the troublesome work of adjusting the incident angle θ each time is unnecessary.

[0010]

An embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an example of the overall configuration of the device of the present invention. The ingot or the work W can be rotated by a chuck 3 (FIG. 7) provided at the tip of the work rotation shafts 2 and 2 extending inwardly from a support D (FIG. 6) installed on the floor. It is subjected to an automatic cylindrical grinding process in the sandwiched state. The work rotating shaft 2 is a motor 2
It is rotationally driven by M. Reference numeral 4 denotes a grinding unit provided corresponding to the ingot or the work W, in which a cylindrical grinding wheel unit 6, an orientation flat grinding wheel unit 8 and a tail shape measuring unit 10 are housed.

Reference numeral 12 is a traverse shaft connected to the grinding unit 4, and as the traverse shaft 12 rotates, the grinding unit 4, that is, the cylindrical grinding wheel unit 6, the orientation flat grinding wheel unit 8 and the tail shape measuring unit 1.
0 is configured to move left and right. The traverse shaft 12 is rotationally driven by a motor 12M. The cylindrical grinding wheel unit 6 is means for grinding the peripheral surface of the ingot or the work W into a cylindrical shape, and a rough grinding wheel 6d attached to the tips of the support shafts 6b and 6c protruding horizontally from the cylindrical grinding wheel unit 6a. It has a precision grindstone 6e. The support shafts 6b and 6c are rotationally driven by a motor 6M.

The orientation flat grinding wheel unit 8 performs orientation flat grinding on a predetermined position of a cylindrically ground ingot or workpiece W. The orientation flat grinding wheel unit 8 is attached to the tip of a support shaft 8b which horizontally projects from the orientation flat grinding wheel unit body 8a. It has a grinding wheel 8c. The support shaft 8b is rotationally driven by a motor 8M. The cylindrical grinding wheel unit 6 and the orientation flat grinding wheel unit 8 have a control shaft 1
4, the cylindrical grinding wheel unit 6 and the orientation flat grinding wheel unit 8 move up and down by the rotation of the control shaft 14 to control the cutting depth of the cylindrical grinding and the cutting depth of the orientation flat grinding. It is supposed to be. The control shaft 14 is rotationally driven by a motor 14M.

As shown in FIG. 2, the tail shape measuring unit 10 has a support shaft 18 having a roll 16 attached to a lower portion thereof.
An upper horizontal plate 20 on which the support shaft 18 is vertically movable, a lower fixing plate 22 mounted below the support shaft 18 in correspondence with the upper horizontal plate 20, and an upper horizontal plate 20. Urging means 24 such as a spring that is interposed between the upper horizontal plate 20 and the support shaft 18 and the lower fixed plate 22 and is interposed between the lower horizontal plate 20 and the lower fixed plate 22. And a sensor 26. The distance detection sensor 26 detects the distance between the upper horizontal plate 20 and the lower fixed plate 22, and is electrically connected to the controller C.
The tail shape measuring unit 10 is means for calculating the grinding depth X according to the shape of the tail W1 in order to perform step processing for forming the step 30 on the tail W1 of the ingot or the work W.

A specific example of calculating the grinding depth will be described with reference to FIGS. For example, when forming a step portion 30 having a length from the edge portion A of the tail portion W1 of the ingot or the work W to the position B horizontally separated by 10 cm, the roll 16 of the tail portion shape measuring unit 10 is first moved to the edge portion A. Then, when the traverse shaft 12 is rotated and the tail shape measuring unit 10 is moved toward the tip of the tail W1, the upper horizontal plate 20 moves horizontally while maintaining its height. On the other hand, the support shaft 18 and the lower fixing plate 22 also move in the horizontal direction.
The downward urging force of 4 also moves downward, that is, as shown in FIG. 2, the roll 16 moves diagonally downward to the position B along the slope of the tail W1.

FIG. 3 shows a state in which the movement of the tail shape measuring unit 10 at this time is detected by the distance detecting sensor 26 and made into a graph. As is clear from the figure, when the 10 mm distance detecting sensor 26 is moved in the horizontal direction on the coordinate of the traverse axis 12, the vertical distance X mm (X = X ₁ −X ₀ : X) detected by the distance detecting sensor 26. ₀ is the value of the distance detecting sensor at the edge A, and X ₁ is the value of the distance detecting sensor at the position B) is the grinding depth. As shown in FIG. 4, the step portion 3 having a length of 10 mm can be obtained by grinding from the edge portion A of the tail portion W1 to a depth of X mm in the vertical direction.
0 is formed.

In FIG. 5, reference numeral 32 denotes a diameter measuring machine for measuring the diameter of the ingot or the work W, which comprises a pair of rotating shafts 3.
Measuring members 38, 4 movably attached to
Has 0. In order to measure the diameter of the ingot or the work W, the rotary shafts 34, 36 are rotated until the measuring members 38, 40 come into contact with the peripheral side surfaces of the ingot or the work W, and the position indexing of the measuring members 38, 40 and the This is performed by detecting the contact stop interval of the measurement members 38 and 40. The rotary shafts 34 and 36 are rotationally driven by motors 34M and 36M.

Reference numeral 42 is an X-ray unit, and as shown in FIG. 6, a slide table 44 installed on the side of the support D.
It is installed on top. The slide table 44 is movable in the direction perpendicular to the axis of the ingot or the work W according to the drive of the motor 42M. The X-ray unit 42 is provided with an arc-shaped goniometer stage 46. An X-ray generator 48 and an X-ray detector 50 are movably attached to the gonio stage 46, and the attachment positions of these X-ray generator 48 and X-ray detector 50 can be arbitrarily adjusted.

Using this X-ray unit 42, the orientation flat orientation is detected. That is, while rotating the ingot or the work W at a slight speed in a predetermined direction, the X-ray generator 48 irradiates the surface of the ingot or the work W at an incident angle θ (23.65 ° in this embodiment). The X-rays diffracted and are detected by the X-ray detector 50 only when the crystal lattice plane of the ingot or the work W coincides with the X-ray incident angle θ. Then, the position of the X-ray diffraction peak detected by the X-ray detector 50 is found, and if the position is found, the rotation of the ingot or the work W is stopped. At this time, for example, when an orientation flat surface is formed on the (110) plane in the case of an ingot having a pulling orientation <111>, the X-ray diffraction peak position of the ingot W coincides with a point on the orientation flat orientation to be obtained. The required orientation flat surface can be obtained by performing orientation flat grinding at the position.

When the X-ray diffraction peak position coincides with the orientation flat orientation as it is, the orientation flat grinding may be performed as it is, but there are cases where the X-ray diffraction peak position does not coincide with the orientation flat orientation. In this case, it is necessary to match the orientation azimuth to be obtained by rotationally positioning the designated angle with the position detected by the X-ray measurement as a reference. For example, in the case of an ingot whose pulling direction is <100> and an orientation flat surface is formed on the (100) plane, the position rotated by 45 ° from the X-ray diffraction peak position of the ingot W is the point on the orientation flat direction to be obtained. If they coincide with each other and the orientation flat is ground at this position, a desired orientation flat surface can be obtained. In the case of the method of detecting the X-ray diffraction peak position as it is as the orientation flat orientation, it is necessary to adjust the X-ray incident angle according to the orientation flat orientation to be detected. For example, in the case of the ingot with the pulling direction of <100> in the above example, when the orientation flat surface is formed on the (100) plane,
The incident angle θ had to be 34.56 °. But,
According to this method, the incident angle θ is fixed at 23.6 °, the reference surface is detected, and then the ingot is rotated again to adjust the angle on the orientation flat grinding surface.
There is an advantage that the troublesome work of adjusting each time is unnecessary. Further, in the case of the ingot of which the pulling direction is <100> in the above example, when the orientation flat surface is formed on the (110) plane, the angle adjustment is unnecessary, so the adjustment angle may be considered to be 0 °.

In FIG. 6, reference numeral 52 denotes a position sensor for detecting the distance to the ingot or the work W, which is attached to the X-ray unit 42 at the axial center position of the ingot or the work W.

The X-ray detector 50 of the X-ray unit 42 is integrally provided with a crystal habit line detection sensor 54 as shown in FIG. The crystal habit line detection sensor 54 is a kind of optical sensor, and detects the presence or absence of the crystal habit line L on the surface of the ingot by irradiating the surface of the ingot with light and receiving the light reflected by the surface. .

C is a controller for controlling each of the above-mentioned devices, and is a motor 2M, 12M, 14M, 34M, 36.
M, 42M and the distance detection sensor 26 are electrically connected. S is a sequencer for performing sequence control. P is an operation panel for inputting information necessary for automatic grinding to the automatic grinding device. The information input from the operation panel P includes a grinding diameter command value, a crystal orientation code, presence / absence of orientation flat grinding, presence / absence of tail step machining, an orientation flat grinding surface angle when performing orientation flat grinding, an orientation flat grinding depth, and the like. Is.

Next, the procedure for carrying out the automatic cylindrical grinding method of the present invention using the automatic cylindrical grinding apparatus having the above-mentioned structure will be described with reference to the flow chart shown in FIG.

First, various kinds of grinding information described above for performing automatic cylindrical grinding of a single crystal ingot or a work W pulled by a single crystal pulling apparatus (not shown), that is, a grinding diameter command value, a crystal orientation code, and an orientation flat grinding. From the operation panel P, the presence / absence, presence / absence of stepped tail processing, the orientation flat grinding surface angle when performing orientation flat grinding, and the orientation flat grinding depth are input.

First, the case where the pulled single crystal ingot W is subjected to cylindrical grinding, tail step processing and orientation flat grinding will be described.

The ingot or the work W is the chuck 3
When both ends of the work are supported by the work rotating shaft 2 via (FIG. 7) (FIG. 1), the ingot or work W is set horizontally and rotatably (step 100), and then the diameter is measured by the diameter measuring machine 32. (Step 101).

The presence / absence of orientation flat grinding is determined from the grinding information input from the operation panel P (step 102). In this example, since orientation flat grinding is present, the rotation of the ingot or the work W is subsequently started, and the crystal is crystallized. The habit line detection sensor 54 detects the position of the crystal habit line L, and the position is stored in the controller C (step 103). The grinding depth is set according to the given grinding diameter command value, and the cylindrical grinding wheel unit 6 performs cylindrical grinding according to this command (step 104). When the cylindrical grinding is completed, the rotation is stopped and the diameter is measured again by the diameter measuring machine 32 (step 105).

It is judged from the input grinding information whether or not tail step processing is performed (step 106). In this example, since tail step processing is present, the shape of tail W1 is measured by the tail shape measuring unit 10. (Step 107), using the cylindrical grinding wheel unit 6, a predetermined stepped tail grinding is performed (Step 108). The presence or absence of orientation flat grinding is again determined from the grinding information input from the operation panel P (step 109),
In the case of this example, since the orientation flat grinding is performed, the work rotating shaft 2 is rotated and the position of the ingot W is adjusted to the crystal habit line position stored in step 103 (step 11).
0). While rotating the ingot W at a very low speed, the X-ray diffraction peak on the side surface of the ingot is detected by the X-ray detector 50 (step 111).

In accordance with the orientation flat orientation information input from the operation panel P, the orientation flat grinding surface (orientation flat grinding means)
Adjust the angle of the ingot W (rotate the ingot at a predetermined angle. When the rotation is unnecessary, the angle is 0) so as to match the installation position of the hula grinding wheel unit 8) (step 1).
After that, the orientation flat grinding is performed using the orientation flat grinding wheel unit 8 (step 113). The margin for orientation flat grinding is measured by the diameter measuring machine 32 (step 114).

The ingot or the work W is attached to the work rotating shaft 2
And then the cylindrical grinding work is completed (step 11).
5).

Further, the case where the tail step processing and the orientation flat grinding are not performed on the single crystal ingot W will be described. Similarly, set the ingot W (step 10
0) and then its diameter is measured (step 101).

The presence or absence of orientation flat grinding is determined from the grinding information input from the operation panel P (step 102). In this example, there is no orientation flat grinding, so step 103 is omitted and cylindrical grinding is performed (step). 104). When the cylindrical grinding is completed, the diameter is measured again (step 10).
5). The presence or absence of tailing step machining is determined from the input grinding information (step 106). In this example, there is no tailing step machining, so steps 107 and 108 are omitted.

Whether or not the orientation flat is ground is determined again from the grinding information input from the operation panel P (step 109). In this example, the orientation flat is not grounded. Therefore, the ingot or the work W is taken out from the work rotary shaft 2. The cylindrical grinding work is completed (step 115).

When either one of the stepped tailing process and the orientation flat grinding is performed on the single crystal ingot or the work W, it is automatically performed according to each work procedure. The description of is omitted to avoid duplication.

[0035]

As described above, according to the present invention, a single crystal ingot is continuously subjected to cylindrical grinding, orientation flat grinding and tail step grinding for cutting out a sample for lifetime measurement. A great effect is achieved in that it can be automatically performed and that the orientation flat grinding or the stepped tail grinding can be freely omitted.

[Brief description of drawings]

FIG. 1 is a block diagram-like explanatory view showing an embodiment of the device of the present invention.

FIG. 2 is a schematic explanatory view showing an example of a tail shape measuring unit of an ingot.

FIG. 3 is a graph showing an example of distance information from a distance detection sensor.

FIG. 4 is an explanatory diagram showing an example when stepped tail grinding is performed.

FIG. 5 is a schematic explanatory view showing an example of a diameter measuring instrument.

FIG. 6 is a schematic side view showing an embodiment of the device of the present invention.

FIG. 7 is an explanatory diagram showing an example of an X-ray unit of the device of the present invention.

FIG. 8 is a partial perspective view of a single crystal ingot.

FIG. 9 is a flowchart showing a procedure for carrying out the method of the present invention.

[Explanation of symbols]

 2 Work rotation axis 3 Chuck 6 Cylindrical grinding wheel unit 8 Orientation flat grinding wheel unit 10 Tail shape measuring unit 32 Diameter measuring machine 42 X-ray unit P Operation panel S Sequencer C controller W Single crystal ingot

Claims (2)

(57) [Claims] 1. A step of: (a) setting an ingot at a predetermined position; (b) measuring a diameter of the set ingot; and (c) determining whether or not to perform orientation flat grinding on the ingot. (D) detecting and storing the crystal habit line position of the ingot, (e) cylindrically grinding the ingot, (f) measuring the diameter of the ground ingot, and (g) ) A step of determining whether or not the tail step grinding is performed on this ingot, (h) a step of measuring the shape of the tail portion of the ingot, and (i) a step of tail step grinding of the ingot, j) a step of judging again whether or not to perform orientation flat grinding on this ingot, (k) a step of aligning this ingot with a habit line storage position, and (l) a direction of the cylindrically ground ingot by X-ray Diffraction peak (M)
Adjust the angle of this ingot to adjust the orientation flat grinding surface .
A step of matching with a hula grinding means ; (n) a step of grinding this ingot to form an orientation flat surface; (o) a step of measuring the formed orientation flat cutting margin; (p) a cylindrical grinding and an orientation flat surface. And a step of taking out the ingot on which the ingot is formed, and when performing cylindrical grinding, orientation flat grinding, and tail step grinding on the ingot based on the input grinding information, the steps (a) to (p) above. The above steps (d) and (k) to (o) are omitted when the orientation flat grinding is not performed, and the above steps (h) and (i) are omitted when the tail step grinding is not performed. An automatic cylindrical grinding method characterized in that 2. Input means for inputting grinding information, means for setting and removing an ingot, means for stopping rotation of the ingot according to the input grinding information, and means for measuring the diameter of the ingot. Means for determining the grinding information, means for detecting the crystal habit line position of the ingot, means for storing the detected crystal habit line position of the ingot, and grinding means for performing cylindrical grinding and stepped tail grinding of the ingot , A means for measuring the shape of the ingot tail, a means for confirming the orientation of the ground ingot by an X-ray diffraction peak, an orientation flat grinding means for grinding the ingot to form an orientation flat surface, and a grinding input for each of the above means And a command unit that sequentially operates based on information.
An automatic cylindrical grinding device, characterized in that the grinding process described above can be automatically executed.